When you use correct punctuation, you help users understand the content
the first time they read it. Following are a few basic guidelines to
apply:

Use a period at the end of sentences, even imperative ones (such as steps).

Use a comma before the last item in a series (known as the serial
comma).

Use a comma to separate independent clauses, and include a coordinating
conjunction (such as and).

Avoid using semicolons. You can almost always use a period in the place of a
semicolon.

Don't use a slash (/) to present a choice among, or a series
of, actions or objects. Rewrite the phrase to eliminate the slash
mark. Exceptions are established terms like client/server and
read/write.

Avoid using exclamation points, question marks, ellipses, or single
quotation marks in regular text. Although these punctuation marks might
appear in code elements, messages, literal commands, or UIs, they're rarely
useful when writing descriptions or instructions for users. One exception is
the use of question marks in FAQ topics.

For specific punctuation guidelines and examples, see Punctuation. For
basic rules about punctuation, see a grammar book, such as the
Harbrace College Handbook.